At a glance: The Customer user ID (CUID) field is a unique user identifier set by the app owner. Use it to cross-reference AppsFlyer attribution data.
Implementing the CUID
- CUID is reported by you to the SDK, thus enabling AppsFlyer to populate the CUID field in raw data reports. To set the CUID in the SDK see: iOS, Android, Unity
- Use the CUID to cross-reference AppsFlyer attribution data with your other data using the CUID as a key.
- Example: A user with two devices has the same CUID. Each time they perform an event on a device, it is recorded using the CUID. This provides you with a holistic view of the user across both devices.
- CUID is used by AppsFlyer Audiences and People-Based Attribution solutions for improved accuracy and targeting.
CUID design and privacy
- AppsFlyer values and respects the privacy of you and your app users.
- We don't collect nor accept personally identifiable information (PII).
- To ensure the privacy of your users, design the CUID without information directly identifying the user. For example, it should not contain the user email address, name, telephone number, social security number, etc.
CUID implementation in the SDK
- Set the CUID in the SDK as soon as possible. Do so because events sent bore this won't have the CUID. The CUID can't retroactively update events recorded without a CUID.
- So that the CUID is part of the original attribution data, set the CUID before calling the
- If you work with integrated data partners, such as Mixpanel or Swrve, the CUID must be set for the integration to work effectively.
Delay SDK init for customerUserID
- You can delay the SDK Initialization until the CUID is set.
- This feature ensures that the SDK doesn't begin functioning until the CUID is provided. If this API (Android, iOS) is used, in-app events and other SDK API calls are discarded until the CUID is provided.
Use this API after considering your business logic and the following pros and cons:
- Attribution data is always associated with a CUID.
- Use the CUID to associate attribution data with other data you have in your systems.
- This allows a more sophisticated use and processing of the data that you get from AppsFlyer.
- Actions and events that users perform, including purchase and subscriptions, aren't recorded in AppsFlyer until CUID is set. This can lead to discrepancies and increases exposure to fraud.
CUID for people-based attribution
AppsFlyer People-based Attribution (PBA) gives you a broad perspective on the impact of web and mobile campaigns, as well as the ability to analyze your efforts to switch web users to your mobile app and vice versa.
You must set the same CUID in both mobile and web, to enable cross-platform insights and analytics.